<template>
  <div
    class="demo-block"
    :class="[blockClass, { 'hover': hovering }]"
    @mouseenter="hovering = true"
    @mouseleave="hovering = false">
    <div class="source">
      <slot name="source"></slot>
    </div>
    <div class="meta" ref="meta">
      <div class="description" v-if="$slots.default">
        <slot></slot>
      </div>
      <div class="highlight">
        <slot name="highlight"></slot>
      </div>
    </div>
    <div
      class="demo-block-control"
      ref="control"
      :class="{ 'is-fixed': fixedControl }"
      @click="isExpanded = !isExpanded">
      <transition name="arrow-slide">
        <i :class="[iconClass, { 'hovering': hovering }]"></i>
      </transition>
      <transition name="text-slide">
        <span v-show="hovering">{{ controlText }}</span>
      </transition>
    </div>
  </div>
</template>

<style lang="scss">
  .demo-block {
    border: solid 1px #ebebeb;
    border-radius: 3px;
    transition: .2s;

    &.hover {
      box-shadow: 0 0 8px 0 rgba(232, 237, 250, .6), 0 2px 4px 0 rgba(232, 237, 250, .5);
    }

    code {
      font-family: Menlo, Monaco, Consolas, Courier, monospace;
    }

    .demo-button {
      float: right;
    }

    .source {
      padding: 24px;
    }

    .meta {
      background-color: #fafafa;
      border-top: solid 1px #eaeefb;
      overflow: hidden;
      height: 0;
      transition: height .2s;
    }

    .description {
      padding: 20px;
      box-sizing: border-box;
      border: solid 1px #ebebeb;
      border-radius: 3px;
      font-size: 14px;
      line-height: 22px;
      color: #666;
      word-break: break-word;
      margin: 10px;
      background-color: #fff;

      p {
        margin: 0;
        line-height: 26px;
      }

      code {
        color: #5e6d82;
        background-color: #e6effb;
        margin: 0 4px;
        display: inline-block;
        padding: 1px 5px;
        font-size: 12px;
        border-radius: 3px;
        height: 18px;
        line-height: 18px;
      }
    }

    .highlight {
      pre {
        margin: 0;
      }

      code.hljs {
        margin: 0;
        border: none;
        max-height: none;
        border-radius: 0;

        &::before {
          content: none;
        }
      }
    }

    .demo-block-control {
      border-top: solid 1px #eaeefb;
      height: 44px;
      box-sizing: border-box;
      background-color: #fff;
      border-bottom-left-radius: 4px;
      border-bottom-right-radius: 4px;
      text-align: center;
      margin-top: -1px;
      color: #d3dce6;
      cursor: pointer;
      position: relative;

      &.is-fixed {
        position: fixed;
        bottom: 0;
        width: 868px;
      }

      i {
        font-size: 16px;
        line-height: 44px;
        transition: .3s;
        &.hovering {
          transform: translateX(-40px);
        }
      }

      > span {
        position: absolute;
        transform: translateX(-30px);
        font-size: 14px;
        line-height: 44px;
        transition: .3s;
        display: inline-block;
      }

      &:hover {
        color: #409EFF;
        background-color: #f9fafc;
      }

      & .text-slide-enter,
      & .text-slide-leave-active {
        opacity: 0;
        transform: translateX(10px);
      }

      .control-button {
        line-height: 26px;
        position: absolute;
        top: 0;
        right: 0;
        font-size: 14px;
        padding-left: 5px;
        padding-right: 25px;
      }
    }
  }
</style>

<script type="text/babel">
import compoLang from '../i18n/component.json'
import { stripScript, stripStyle, stripTemplate } from '../strip'
const version = '2.5'
export default {
    data() {
        return {
            jsfiddle: {
                script: '',
                html: '',
                style: ''
            },
            hovering: false,
            isExpanded: false,
            fixedControl: false,
            scrollParent: null
        }
    },

    methods: {
        scrollHandler() {
            const { top, bottom, left } = this.$refs.meta.getBoundingClientRect()
            this.fixedControl = bottom > document.documentElement.clientHeight &&
          top + 44 <= document.documentElement.clientHeight
            this.$refs.control.style.left = this.fixedControl ? `${left}px` : '0'
        },

        removeScrollHandler() {
            this.scrollParent && this.scrollParent.removeEventListener('scroll', this.scrollHandler)
        }
    },

    computed: {
        lang() {
            return this.$route.path.split('/')[1]
        },

        langConfig() {
            return compoLang.filter(config => config.lang === 'zh-CN')[0]['demo-block']
        },

        blockClass() {
            return `demo-${this.lang} demo-${this.$router.currentRoute.path.split('/').pop()}`
        },

        iconClass() {
            return this.isExpanded ? 'el-icon-caret-top' : 'el-icon-caret-bottom'
        },

        controlText() {
            return this.isExpanded ? this.langConfig['hide-text'] : this.langConfig['show-text']
        },

        codeArea() {
            return this.$el.getElementsByClassName('meta')[0]
        },

        codeAreaHeight() {
            if (this.$el.getElementsByClassName('description').length > 0) {
                return this.$el.getElementsByClassName('description')[0].clientHeight +
            this.$el.getElementsByClassName('highlight')[0].clientHeight + 20
            }
            return this.$el.getElementsByClassName('highlight')[0].clientHeight
        }
    },

    watch: {
        isExpanded(val) {
            this.codeArea.style.height = val ? `${this.codeAreaHeight + 1}px` : '0'
            if (!val) {
                this.fixedControl = false
                this.$refs.control.style.left = '0'
                this.removeScrollHandler()
                return
            }
            setTimeout(() => {
                this.scrollParent = document.querySelector('.page-component__scroll > .el-scrollbar__wrap')
                this.scrollParent && this.scrollParent.addEventListener('scroll', this.scrollHandler)
                this.scrollHandler()
            }, 200)
        }
    },

    created() {
        const highlight = this.$slots.highlight
        if (highlight && highlight[0]) {
            let code = ''
            let cur = highlight[0]
            if (cur.tag === 'pre' && (cur.children && cur.children[0])) {
                cur = cur.children[0]
                if (cur.tag === 'code') {
                    code = cur.children[0].text
                }
            }
            if (code) {
                this.jsfiddle.html = stripTemplate(code)
                this.jsfiddle.script = stripScript(code)
                this.jsfiddle.style = stripStyle(code)
            }
        }
    },

    mounted() {
        this.$nextTick(() => {
            let highlight = this.$el.getElementsByClassName('highlight')[0]
            if (this.$el.getElementsByClassName('description').length === 0) {
                highlight.style.width = '100%'
                highlight.borderRight = 'none'
            }
        })
    },

    beforeDestroy() {
        this.removeScrollHandler()
    }
}
</script>
